Field of the Invention
The present invention relates to an image projector.
Description of the Related Art
An image projector projects a light modulated by a light modulation element (image forming element) such as a liquid crystal panel onto a projection surface such as a screen using a projection optical system so as to display a projection image.
Adjusting projection conditions, such as an orientation and a tilt of the image projector, and a projection optical system to vary a projection size and a projection position enable a user to display a projection image on a desired region in a projection surface.
However, adjusting the projection conditions may cause geometric distortions (for example, trapezoidal distortions) in the projection image.
Japanese Patent Laid-Open No. (“JP”) 2003-195416 discloses a projection type display apparatus that corrects image distortion according to a lens shift quantity to control screen distortion generated by a tilt projection.
A method of JP 2003-195416 can continue to correct image distortion even accurately if a lens shift is performed while correcting screen distortion generated by a tilt projection.
However, the method of JP 2003-195416 fails to consider a direction where a projection image on a projection surface shifts, and thus the projection image shifts in a direction different from a direction intended by a user.